Were it not for the observance of the Octave of Easter, today would have the Feast of the Annunciation.
However, did you know that today is the feast day of St. Dismas the "Good Thief"?
Here is his entry from the Martyrologium Romanum:
2. Commemoratio sancti latronis, qui, in cruce Christum confessus, ab eo meruit audire: "Hodie mecum eris in paradiso".